I bought the dress at a store locally. I wear a small in the shirts and hoodies, and I fit a small dress, so I would say the sizing is consistant.
I will say the dress doesn't photograph well and didn't look as I thought it would in person. It's not fitted, as it would appear in the pictures online; it's a bit more loose/smock-like. That being said, I liked it anyway. It is a little plain, but I bought it for work. It would look great with tights or leggings and boots (ankle or knee-high).
I am considering having it taken in a little bit to give it more of a fitted look, but it looked good on me as it was. (Also, it was only like $55, so I figured why not?)